[Gritty]

Chemical and biological weapons cannot do this in the stated proportions.

Not true. The right ones with the right disperal methods can cause calamitous damage and casualties.

Visualize smallpox....

[Trust but Verify]

Smallpox would, again, have been an effective weapon prior to 9/11. Now, if people started showing up with smallpox-like symptoms, it is MUCH more likely it would be properly diagnosed, and promptly. Quarantines, vaccination programs and new drugs to combat the disease almost make smallpox a waste of time for terrorists.